unicellular

adjective

uni·​cel·​lu·​lar ˌyü-ni-ˈsel-yə-lər 

: having or consisting of a single cell

unicellular microorganisms

Examples of unicellular in a Sentence

Recent Examples on the Web

From a technical point of view, brewer’s yeast is a collection of microscopic, nonpathogenic unicellular fungi known by the scientific name saccharomyces cerevisiae, which can be used in an active or inactive form. —Beatrice Zocchi, Vogue, 16 Apr. 2025

How life evolved from unicellular to multicellular organisms remains a mystery, though evidence indicates that this may have occurred multiple times independently. —Steven Strogatz, Quanta Magazine, 20 Mar. 2025

But in any case, one question then is how does a unicellular organism manage to make this transition, in any of these cases? —Steven Strogatz, Quanta Magazine, 20 Mar. 2025

This would mean that the transition from unicellular to multicellular life was not a leap requiring entirely new genes but rather an evolutionary refinement of existing genetic mechanisms. —Scott Travers, Forbes, 11 Dec. 2024

Word History

First Known Use

1858, in the meaning defined above

Rhymes for unicellular

• extracellular
• intercellular
• intracellular
• multicellular
• acellular
• subcellular
• cellular
• hepatocellular

Kids Definition

unicellular

adjective

uni·​cel·​lu·​lar ˌyü-ni-ˈsel-yə-lər 

: having or consisting of a single cell

unicellular microorganisms

Medical Definition

unicellular

adjective

uni·​cel·​lu·​lar ˌyü-ni-ˈsel-yə-lər 

: having or consisting of a single cell

unicellular microorganisms

unicellularity

-ˌsel-yə-ˈlar-ət-ē 

noun

plural unicellularities